The statements in this section merely provide background information related to the present disclosure and may not constitute prior art.
Typically, both side portions of an automobile body include a roof edge disposed in the upper section of the automobile body, a side sill disposed in the lower section of the automobile body, and pillars that connect the roof edge and the side sill, whereby a framework for a passenger compartment is formed. Thus, the side sills contribute to the passenger compartment framework and determine the stiffness of the automobile body, both during normal use and in case of a crash involving a frontal impact, an offset impact, or a side impact wherein generally the side sill receives an overload. For example, the deformation of the passenger compartment framework of an automobile that occurs when another vehicle collides against the side thereof needs to be restrained to a minimum level, and the reinforcement of the side sill plays a crucial role.
In automobiles currently manufactured, side sills are typically made of steel, being assembled with additional parts such as crash boxes for absorbing impact energy. While steel has the strength and stiffness required, it is also heavy and therefore contributes significantly to the overall weight of the automobile. In order to reduce weight, some recently marketed automobiles include side sills made of carbon-fiber reinforced plastics such as epoxy and vinyl ester. However, due to the different physical properties of these materials as compared to steel, existing manufacturing lines for automobile bodies can no longer be used or have to be modified in complex ways.
For example, whereas in conventional manufacturing methods an automotive body including steel side sills is first assembled into a so-called body in white, which then undergoes painting and baking at a temperature approximately 190° C., side sills comprising epoxy or vinyl ester, which are stable only up to a temperature of approximately 120° C., can be mounted to the automobile body only in a separate assembly procedure after baking has completed and furthermore require a separate painting process using a non-baked paint of generally lower durability.